Knife sharpener for asian and european/american knives

Abstract

A knife sharpener sharpens a wide range of knives and blades. The knife sharpener includes an angle guide associated with a first stage abrasive surface at an angle in the range of 12-18 degrees. A second stage is provided at an angle in the range of 17-23 degrees. A third stage is provided at an angle in the range of 19-25 degrees. The abrasive surface in the first and second stages is in the range of 240 to 400 grit while the abrasives in the third stage is in the range of 600 to 2000 grit.

What is claimed:  
     
       1. A precision manual knife sharpener for selectively sharpening with the same sharpener knives and blades representative of two widely different style of knives having different factory made primary edge facets established at widely different primary angle A and primary angle B, said sharpener comprising a first stage having a first stage disk with an abrasive surface for sharpening a first primary angle facet blade edge of a first knife, a first knife angle guide in said first stage to position the blade edge facet of the first knife into contact with said first stage abrasive surface to establish the first primary angle facet along the blade edge, said first stage guide located with respect to the first abrasive surface at an angle A which is in a range no greater than 18 degrees, said first stage abrasive surface having its abrasive surface from abrasives in the range of 240 to 400 grit, a second stage having a second stage disk with an abrasive surface for sharpening a second primary angle facet blade edge of a second knife, a second knife angle guide in said second stage to position the edge facet of the second knife into contact with said second stage abrasive surface to establish the second primary angle facet along the blade edge, said second stage guide located with respect to the second stage abrasive surface at an angle B which is greater than angle A, a third stage having a third stage disk with an abrasive surface for selectively sharpening the blade edge of the respective first knife and second knife to create a microscopic bevel at the tip of the blade edge of the respective first knife and second knife, a third knife angle guide in said third stage to position the blade edge facet into contact with said third stage abrasive surface, said third stage guide located with respect to the third stage abrasive surface at an angle C which is at least as great as the angle B of the second stage and which is at least 5 degrees greater than angle A of the first stage, and said third stage disk having its abrasive surface formed from ultra fine abrasives. 
     
     
       2. The sharpener of  claim 1 , wherein said angle A is about 15 degrees, said angle B being about 20 degrees, and said angle C being about 22 degrees. 
     
     
       3. The sharpener of  claim 1 , wherein the abrasives of all said stages are 100% diamonds. 
     
     
       4. The sharpener of  claim 1 , wherein the abrasives of all said stages contain diamonds. 
     
     
       5. The sharpener of  claim 1 , wherein said abrasive surface in each of said first stage and said second stage and said third stage is part of a sharpening element in each of said stages, said sharpening element comprising a pair of disks mounted on a rotatable shaft supported by appropriate bearings, and said disks faced with an abrasive coated member contoured nominally on its outer coated surface as a truncated cone press-fitted onto said shaft with the smaller end of each disk's coated surface in nominal physical contact so that the knife passes through at a non-perpendicular angle to said shaft. 
     
     
       6. The sharpener of  claim 5  for sharpening knives where the abrasive coated members are metal stampings with an abrasive coating on the outer surface of their contour. 
     
     
       7. The sharpener of  claim 6  for sharpening knives where the disks are supported onto the rotating shaft by means of a plastic hub that is an integral part of said disks and said shaft is knurled to secure the disks onto said shaft. 
     
     
       8. The sharpening element of  claim 5  for sharpening knives where said angle is from 10 to 15 degrees off axis. 
     
     
       9. The sharpener of  claim 1 , wherein said third stage disk is a rigid disk. 
     
     
       10. The sharpener of  claim 1 , wherein angle B is in the range of 17-23 degrees, angle C being in the range of 19-25 degrees but being greater than angle B and being at least 5 degrees greater than angle A, angle A being in the range of 12-18 degrees, said second stage disk having its abrasive surface formed from abrasives in the range of 240 to 400 grit, and said third stage disk having its abrasive surface formed from ultra-fine abrasives in the range of 600 to 2000 grit. 
     
     
       11. The sharpener of  claim 1  wherein angle A is about 15 degrees. 
     
     
       12. The sharpener of  claim 1  wherein angle C is 7 degrees greater than angle A. 
     
     
       13. The sharpener of  claim 1  wherein said third stage disk is press-fit on a rotatable shaft. 
     
     
       14. A method of selectively sharpening first and second knives with the same sharpener wherein the first knife has a different primary angle facet than the primary angle facet of the second knife, comprising providing the sharpener of  claim 1 ; for sharpening the first knife, sharpening the first knife in the first stage to create a primary angle facet at angle A, then sharpening the first knife directly in the third stage without sharpening in the second stage to create a microscopic bevel at the tip of the primary angle facet at angle C; for sharpening the second knife, sharpening the second knife first in the second stage to create a primary bevel at angle B without sharpening in the first stage, and then sharpening the second knife directly in the third stage to create a microscopic bevel at the tip of the primary angle facet at angle C. 
     
     
       15. The method of  claim 14  wherein the first knife is an Asian/Japanese style knife and the angle A is about 15 degrees, the second knife is a Euro/American style knife and the angle B being about 20 degrees, and the angle C being about 22 degrees. 
     
     
       16. The method of  claim 14 , including forming the microscopic bevel only in the lower 20-30% of the facet length adjacent the primary angle facet. 
     
     
       17. The method of  claim 14  wherein angle B of the sharpener is in the range of 17-23 degrees and angle C is in the range of 19-25 degrees but the angles selected for angles A and B and C are such that angle C is greater than angle B and angle C is at least 5 degrees greater than angle A, the second stage disk grit size being in the range of 240-400 grit and the third stage disk grit size in the range of 600 to 2000 grit, selecting as the first knife an Asian/Japanese style knife having a primary angle facet at the angle of angle A, and selecting as the second knife a Euro/American style knife having a primary angle facet at the angle of angle B. 
     
     
       18. The method of  claim 14  wherein the first knife is an Asian/Japanese style knife having a primary angle facet of about 15 degrees, and angle A is about 15 degrees. 
     
     
       19. The method of  claim 14  wherein angle C is 7 degrees greater than angle A. 
     
     
       20. The method of  claim 14  wherein the third stage disk is press-fit on a rotatable shaft, and rotating the shaft as the respective knife is drawn back and forth. 
     
     
       21. A sharpening element for sharpening knives that have a double faceted cutting edge comprising a pair of disk assemblies mounted and secured on a rotatable knurled shaft supported by appropriate bearings, each of said disk assemblies comprising a contoured plastic hub fitted and faced with a metal stamping coated with a single grit diamond abrasive and contoured to match the contour of the outer surface of said hub and shaped nominally on its said outer coated surface as a truncated cone, said assemblies being press-fitted onto said shaft with the smaller end of each disk assembly's abrasive coated metal stamping surface in nominal physical contact with each other so that the knife to be sharpened passes in contact simultaneously with the diamond abrasive surfaces on each assembly at a non-perpendicular angle to said shaft. 
     
     
       22. The sharpening element of  claim 21 , wherein said sharpening element is the sharpening element in each stage of a three stage sharpener. 
     
     
       23. The sharpening element of  claim 22 , wherein said sharpener is a manual sharpener. 
     
     
       24. The sharpening element of  claim 21 , wherein said non-perpendicular angle is from 10 to 15 degrees off axis.